Physics

Problem

A two-dimensional light ray is represented by the vector

\mathbf v = 3\hat{i}-4\hat{j}

before it strikes a perfectly reflecting surface that lies along the line

y = x

. Which vector best represents the direction of the reflected ray? a)

3\hat{i}+4\hat{j}

-4\hat{i}+3\hat{j}

4\hat{i}-3\hat{j}

-3\hat{i}+4\hat{j}